You’re more than likely aware that your baby should have either breastmilk or formula exclusively for roughly their first six months, until complementary solid food is introduced. The American Academy of Pediatrics, the World Health Organization, UNICEF, and most health organizations recommend exclusive breastfeeding (or formula feeding) for the first six months of life. But there’s a lot of advice online and recommendations from pediatricians that say you can go ahead and give your baby solids starting at 4 months. So, is it 4 months, 5 months, or 6 months?? Is there a perfect time? Will any harm be caused by starting early at 4 months? What about starting later at 7 months? Let’s talk through these questions!

Why It’s Recommended to Start Solids at 6 Months

There are two main reasons why waiting till around 6 months to start solids is a good idea. Firstly, this is likely when your baby will be ready from a motor development standpoint (we talk more about that in this blog!). Secondly, from a nutrition lens, breastmilk or formula provides everything your baby needs until 6 months. There really is no nutritional benefit to starting solids early. (1)

Note: If your baby was born premature, you will want to use their adjusted age for helping you determine readiness (e.g., If baby was born at 32 weeks, baby is 2 months premature. Baby’s chronological age would be 6 months when their adjusted age is 4 months. Their chronological age would be 8 months when their adjusted age is 6 months. Most premature babies “catch up” over time, but making sure that they are developmentally ready for solids is important moreso than their chronological age. Some premature babies may be more ready for solids when they are 6 months adjusted).

Motor Development is Important

There are certain gross motor skills that are important for baby to develop before starting solids, and, for most babies, those skills aren’t usually present before 6 months. Some babies may not show all of these skills until around 7 months! First and most importantly, baby should be able to sit unsupported for a few minutes. Sitting alone on the floor for a few minutes indicates that they have the head, neck and trunk strength and control necessary for safe swallowing. And it means that they can independently bring items to their mouth, because their core is strong enough to sit without support from the hands. Most babies younger than 6 months of age do not have the necessary motor skills for starting solids, and, therefore, are not physiologically ready to swallow anything besides breast milk or formula. Oftentimes when babies are offered foods before they are ready from a motor standpoint, they are what we call “passive participants in eating.” This means that you may be able to feed a spoonful of purees into their mouths, but baby isn’t able to feed themselves just yet, so they are not able to “actively participate” in meals.

Baby should also be showing an interest in food, along with bringing teethers and toys to their mouth. Development of these big gross motor skills means that baby is ready to work on the fine motor skills required during eating.

*Note- If baby is not sitting independently by the time they turn 7 months - talk to your pediatrician about a referral to a physical therapist or an occupational therapist. You can talk with one of our specialists here.

Nutritional Needs for Solids at 6 Months

So, if breastmilk and formula are all babies need for the first 6 months and provide the perfect nutrition for optimal growth and development, then what changes around 6 months? Why are solids necessary around the 6 month mark?

Around 6 months, the energy and nutrient needs of babies start to increase, and introducing solid food helps to supplement what baby is getting from breast milk and/or formula. The two main nutrients that baby needs more of are iron and zinc. (2) Most babies will have adequate iron stored up until 6 months, at which time the iron baby gets from breastmilk is no longer adequate. Breast milk is lower in iron than formula, but the iron in breast milk is better absorbed. (2) Depending on how much formula baby is drinking, it is possible that their iron needs are met through iron-fortified formula.

Regardless of whether baby is breastfed, formula fed or a mix of both, at around 6 months they will benefit from an additional source of iron.

Read here about the best sources of iron to feed baby.

Gut Maturity

Another thing to take into consideration is the maturity of your little one’s digestive system and how well equipped it is to handle food other than breast milk and/or formula. Prior to 6 months, solid foods are not well digested and absorbed because the digestive enzymes and stomach acid needed for digestion are not yet at full capacity. (3)

Additionally, your baby has what is called an “open-gut” prior to around 6 months. A great description from the Healthy Horizons website explains “that there are spaces between the cells of the small intestine which allow proteins and pathogens to pass into the bloodstream. This allows beneficial antibodies from breastmilk to pass into the bloodstream, but it also means that proteins and pathogens from solid food can also pass through. This can make your baby more susceptible to allergies and illnesses. The proteins and antibodies from breastmilk coats and fits into those openings, and gives your baby a passive immunity to prevent illnesses and allergic reactions before the gut closes. At age 6 months, your baby can start producing these antibodies on his or her own and the gut has closed by this time.” (4)

My Pediatrician Says My Baby Is Ready For Solids At 4 Months

This is a scenario that happens all the time. You go in for your baby’s 4 month wellness check-up- starting solids might not even be on your radar yet- and then your pediatrician says you should go ahead and start giving your baby foods. Usually the first recommendation they give is starting with….. rice cereal. Remember that just because your pediatrician (or really anyone!) recommends something, does not mean you have to do it. You get to make the ultimate decision about what’s best for you and your family.

Secondly, the truth is that the majority of pediatricians are not well-educated on infant nutrition (which is why feeding specialists and registered dietitians exist!) Rice cereal has been recommended in the past because it is fortified in iron and it is not an allergenic food, but we know from current guidelines that rice cereal is no longer recommended as a first food as it is processed and not nutritionally beneficial, and this is now outdated advice (5).

Is Starting Solids Early Warranted With Weight Gain Concerns?

If you go to the pediatrician for a well check, and they bring up concerns about baby’s weight or growth curve, that can be overwhelming. Depending on your baby’s age, they may recommend starting solids early in an effort to supplement calories and promote weight gain. This decision is absolutely one to be made in conjunction with your baby’s provider, but again, they may not be the most educated provider when it comes to breastfeeding and weight gain. So, it might be a good idea to talk with a registered dietitian to discuss options as well.

Starting solids early is likely not the best option to help with weight gain, even if your little one is 4 months old or older. Not gaining sufficient weight from breastmilk or formula alone is not a reason to start solids in most cases. This scenario is a perfect example: Baby’s stomach capacity is low, so if offering pureed foods, you will likely fill their stomach up on lower calorie solid foods (there are 10-15 calories in a few teaspoons of a vegetable puree) when they could be getting more calorically and nutrient-dense breastmilk or formula (which contain 70 calories per 3.3 oz). Babies starting solids don’t eat many bites of food! If baby’s stomach did not get filled with solid food, they would have been able to consume more breastmilk or formula which is higher in calories and protein and would help with weight gain.

Oftentimes baby just needs to be monitored or supported in drinking more breastmilk or formula. That can be done with support from a feeding specialist or lactation consultant. If you have a baby diagnosed with growth faltering or failure to thrive, you should be working with a pediatric dietitian and lactation consultant- they are the ones that will help you fortify your baby’s milk supply.

You can meet with those professionals on our team here:

Starting Solids Early Risks More Harm Than Good

There really are no benefits to starting solid foods early, only the potential for harm, such as an increased risk of choking, food allergies, GI infections, and improperly digested food. (3) Does this mean that if you start solids a day or a week before your baby is 6 months they are going to experience all these drawbacks? No, likely not. There is no perfect day or exact age that starting solids is best - it is more of a window of time with right around ~ 6 months being the goal, and making sure baby has the important gross motor skills developed for safe swallowing and mealtime participation.